Mortar mill



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S. B. LADD. MORTAR MILL.

No. 524,683. y Patented Aug. 14, 1894.

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y S. B. LADD.

MORTAR MILL. No. 524,683. Patented Aug. 14, 1894.

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3 Sheets-Sheet 3. S. B. LADD. MORTAR MILL.

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. No. 524,683. Patented Aug. 14, 1894.

UNITED STATES PATENT OEEiCE.

STORY B. LADD, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR OF ONE-HALF TO GEORGE HUGHES, OF SAME PLACE.

MoRTAR-MI'LL.

SPECIFICATION forming part of Letters `Patent No. 524,683, dated August 14, 1894. Application iiled March 21, 1,894.; Serial No. 504,492. (No model.)

To @ZZ whom t may concern.-

Bcit known that I, STORY B. LADD, a citizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Mortar-Mills; and I do hereby -declare the following to be a full, clear, and exact description of the invention,such as willenable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to `the figures of reference marked thereon, which form a part of this specification.

The object of the present invention is to I5 provide a mill for the grinding and mixing of plastic material, as for example mortar, which shall be continuous in its operation, that is have a continuous feed and continuous discharge, and which shall also grind the mateze rials, as well as knead or mix them; and this result I secure by means of an annular grinding pan or trough having continuously re volving appliances for grinding and mixing the material; said pan having means for continuously feeding the raw material onto the iioor of the pan at a certain point, and also a free discharge of all material from the floor of the pan at a point just behind the feeding point; so that the raw material, under the action of the rollers and plows or other devices, travels, in a steady flow, from the point of entrance around to the point of discharge, Where all the material is freely discharged in a properly mixed condition. Thus it will be seen that, when the mill is in operation,there is a steady iiow of material in progressive stages of manufacture, from the raw material at the point of entrance, to the finished product at the point of discharge.

The invention further consists of certain details of construction and arrangement all lof which will be fully described and then pointed out in the claims.

In the accompanying drawings: Figure 1 is I a plan view of a mill embodying the features of the present invention. Fig. 2 is a sectional view of the same taken on the line 2-2; and Fig. 3 is a view partly in section and partly in elevation, the section being taken on the 5o broken line 3-3-3.

The grinding and mixing pan, 10,- is of annular form, in which there travel two gangs of rollers, 1l, 11, loosely mounted on a horizontal shaft 12, which shaft is carried by the central vertical shaft 13. In the present case there are three rollers in each gang, set with the spaces, 14, therebetween, a little narrower than the width of one of the rollers, 1l; and the outer roller of one of the gangs travels close to the outer rim of the 4annular pan, 6o while the inner roller of the other gang travels close to the inner rim of the annular pan, the rollers of one gang traveling over the ground represented by the spaces between the rollers of the other gang. 6:

The horizontal shaft 12, carrying the gangs of rollers, is connected to a vertical shaft, 13, by the spline or feather 15, which admits of the shaft 12 rising and falling on the driving shaft, in order that the rollers can rise suii- 7o ciently to pass over any obstruction or accu mulation of material in the pan. The outer edges of the splines, 15, have a slight curvature in a vertical plane to allow for the free liftingpf one end of the shaft sufficiently to permit the rollers to travel easily.

Above the roller shaft 12, there is a horizontal beam 20, at right angles to the roller shaft, rigidly keyed to the vertical shaft 13, and deflected downward at the ends, over the 8o runway of the pau. This beam carries at each end a set of plows, 21, equal in number to the rollers, and also a side plow or scraper 22. The plows 2l, are set so as to follow in the spaces between the rollers of the gang imme- 8 5 diately preceding them and cutthrough the middle of the ridges left in the material to be mixed by the gang of rollers in advance of them. The action of a gang of rollers is to force the material ahead to a certain extent, 9o and to crowd it outward and into the open spaces between them, leaving the semi-plastic material in ridges; and the gang of plows, following a gang of rollers,are set so as to cut through these ridges and turn the material over to either side. The side scraper, 22, carried by one arm of the cross beam is set close to the outer edge of the pan, and that carried by the other arm of the beam is close to the inner edge, so as to turn the material roo at the sides into the path of the rollers following. A

The ends of the plow beam are dropped in the manner shown so as to bring the plows down to the level of the pan and yet' permit the beam to be attached to the center shaft above the roller shaft. The vbrace rodsV 23 support and strengthen the ends of the plow beam.

Attached to each end of the plow beam, in the rear of each gang of plows, there is a pair of adjustable leveling scrapers 25,V projecting obliquely rearward from the plow supporting beam and supported at their rearward ends by the brackets 26.Y These leveling scrapers-a-re set at some distance above the floor of the pan, and are only designed to out the tops of the ridges and level the material off. The scraper blades on one side are setat` such an angle as to force the material outward, towardv the outer rim of the pan; While on the other sidethe blades are set so as to scrape the material, that is high enough for` them to reach, inward toward the center of the pan.

The action of the rollers, plows and leveling scrapers is'as follows: First the rollers, crushing and grinding, the material leaves. it in ridges. Then the plows cut through these ridges and turn the material over still leaving it in furrows,A unless it is sufficiently plastic to settle level, andk the leveling scrapers following force the tops of the ridges over into the furrows and leave the material essentially level for the action of the gang of rollers following.

The driving shaft,r13, has a large gear, Y17,V

driven by the pinion,18, on the power shaft, 19. It is properly supported by the bearing, 27and the step 28. f

The feed hopper is shown at 30;' the same having a discharge spout, 3l, delivering the rawv material onto the iioor ofthe pan. 32 is a gate for the hopper with handle 33,. and 34 andk 35 are bucket elevators for the sand and lime, or other raw material, delivering the same in measured quantities into the hopper.

The arrow indicates the direction in which the gangs of rollers and plows revolve. In the fioor of the pan behind the feed hopper, or in other words just before reaching the mouth ofthe supply hopper, when following the course of'- the rollers and plows,there is-a discharge opening extending entirely across the annular pan from the inner to the outer edge thereof, and bridged by the steel'bars-il, said barsbeing flush with the floor of" the pan. 43 is a chute through which the material is discharged. This grated opening is notV designed to be a griddle, or screen, which shall only allow material of a certain size to pass through, but the openings between the bars are large enough to permit all material to pass through that reaches them and to clear the floor of the pan. The grate bars are simply Yforl the purpose of bridgingV the opening in order that the rollers can pass over the same. Having thus described my invention, what I claim asnew is- 1. In a mill for plastic material, an annular pan hav-inga feed delivering the raw material into t-hepan at a certain point, and a free discharge opening for all material from the iioor of the pan behind the feeding point, in combination with rollers revolving therein, as and for the purpose set forth.

2. In a mill for plastic material, an annular pan having a feed delivering the raw material into the pan` at a certain point, and a series of discharge openings in the iioor of the pan extending across the annular channel behind the feeding point, in combination with a gang of rollers revolving in the pan, substantially as-and for the purpose set forth.

3,. In a mill for plastic material, an annular pan, having a feed delivering the raw material into the pan at a certain point, anda free discharge opening for all material from the floor of the pan behind the feeding point, in combination witha center shaft having a horizontal shaft vertically movable thereon with gangs ot' rollers carried by said horizontal shaft, and a plow beam fixed to the vert-ical shaft and carrying gangs of plows, substantially as and for the purpose set, forth.

4'.. In a mill for plastic material, an annular pan having a feed delivering the raw material into the pan at a certain point, and a free discharge Yopening for all material from the iioor of the pan behind the feeding'point, in combination with a center shaft having a horizontal Shaftvertically movable thereon with gangs of rollers carried by said horizontal shaft, and a plow beam fixed to the vertical shaft and' carrying gangs of plows, together with obliquely inclined levelin g bladesbehind thegangs of plows, substantially as and for the purpose set forth.

5. In amill for plastic material an annular pan having a feed hopper, and a series of discharge openings in the floor ofthe pan extending across the annular channel behind the feedhopper, incombination with a center shaft, a horizontal shaft vertically movable on the center shaft and carrying at each end IOO a gang of rollers, and a plow beam fastened Witnesses:

yOLIVER'VV. BAILEY,

Trios. S. HOPKINS. 

